CN103102233B

CN103102233B - Method of preparing n-tetradecane or n-hexadecane from natural acid

Info

Publication number: CN103102233B
Application number: CN201110353465.1A
Authority: CN
Inventors: 张志银; 孙剑锋; 全辉; 姚春雷; 赵威; 林振发
Original assignee: China Petroleum and Chemical Corp; Sinopec Fushun Research Institute of Petroleum and Petrochemicals
Current assignee: China Petroleum and Chemical Corp; Sinopec Fushun Research Institute of Petroleum and Petrochemicals
Priority date: 2011-11-10
Filing date: 2011-11-10
Publication date: 2015-01-14
Anticipated expiration: 2031-11-10
Also published as: CN103102233A

Abstract

The invention relates to a method of preparing n-tetradecane or n-hexadecane from natural acid. According to the invention, the natural acid and a solvent are mixed and then undergo a hydrogenation reaction in the presence of a catalyst and hydrogen, wherein the catalyst is a palladium/carbon nanotube catalyst, reaction pressure of the hydrogenation reaction is 1 to 10 MPa, reaction temperature is 220 to 320 DEG C, reaction time is 3 to 10 h, the catalyst uses a multi-walled carbon nanotube as a carrier and 2 to 10% by mass of palladium as an active component, and the solvent is one selected from the group consisting of hexane, n-heptane, n-octane and dodecane. Compared with the prior art, the method provided by the invention has the advantages of simple preparation technology, a low reaction temperature, a small usage amount of the solvent, high reaction activity and high yield of a target product.

Description

The method of n-tetradecane hydrocarbon or n-hexadecane hydrocarbon prepared by a kind of natural acid

Technical field

The present invention relates to a kind of natural acid generates n-tetradecane hydrocarbon or n-hexadecane hydrocarbon method through liquid phase catalytic hydrogenation deoxidation, belong to catalysis technical field.

Background technology

Normal paraffin is as one of the key ingredient of diesel oil at low-temperature improving agent and environmental protection liquid fuel composition, obtained and applied widely, normal paraffin monomer also plays extremely important effect at analysis fields such as geology, crude oil, Atmospheric particulates and organism simultaneously.And n-tetradecane hydrocarbon and n-hexadecane hydrocarbon are as a kind of normal paraffin containing high carbon atom number, except there is such use, be also applied to the field such as pharmaceutical intermediate, phase change material.

The preparation method of the normal paraffin of current existence mainly contains following several: one, take molecular sieve or urea dewaxing to prepare the mixture of normal paraffin, and then carry out that segmentation is freezing, the method for separating normal alkane monomer, wherein typical technique has the molex technique of Vop company, and the independently developed IVDW technique of China; Two, Woertz is taked to react the symmetrical normal paraffin of preparation; Three, alkane iodide method of reducing is adopted; Four, use sherwood oil and normal hexane, normal heptane makes solvent link haloalkane method.

Although above method can obtain corresponding normal paraffin monomer, all there is certain problem in each method: as first method processing condition more complicated, requires very high to some equipment, material; Second method is only applicable to symmetry even number alkane, and generate item needs ether solvent repeatedly to extract; Third and fourth kind of method operational danger is large, and sherwood oil very easily erupts in sodium Metal 99.5 and haloalkane vigorous reaction, and safety coefficient is low, and cost is higher.

Corresponding alkane can be prepared with higher fatty acid ester through hydrogenation, but in hydrogenation process, a large amount of decarboxylic reactions and decarbonylation reaction can be there is, reaction product is formed complicated, the alkane that more carbon number reduces can be produced, be unfavorable for the productive rate improving object product on the one hand, decarboxylic reaction and decarbonylation reaction can produce carbon monoxide or carbonic acid gas on the other hand, can produce adverse influence to hydrogenation reaction.

CN200910100260.5 discloses a kind of method of preparing alkane by high fatty acid ester, with the fatty acid methyl ester containing 8 ~ 22 carbon atoms or containing the fatty-acid ethyl ester of 8 ~ 22 carbon atoms for raw material, carry out hydrogenation reaction and produce alkane, but can find out, in the alkane product obtained, carbon in lipid acid still has major part to be removed, and as taken Uniphat A60 as raw material, the pentadecane hydrocarbon obtained and the total recovery of hexadecane hydrocarbon are 84%; Be raw material with Laurate methyl, the hendecane hydrocarbon obtained and the total recovery of 12 carbon alkanes are 72%.Therefore, the yield of the product (hendecane hydrocarbon, 12 carbon alkanes, pentadecane hydrocarbon, hexadecane hydrocarbon) of non-decarburization direct hydrogenation can be lower.Meanwhile, the boiling point of hendecane hydrocarbon and 12 carbon alkanes, pentadecane hydrocarbon and hexadecane hydrocarbon difference is very little, obtains hendecane hydrocarbon, 12 carbon alkanes, pentadecane hydrocarbon, hexadecane hydrocarbon are very difficult further by isolation technique.

Summary of the invention

For the deficiencies in the prior art, the invention provides a kind of method that natural acid prepares n-tetradecane hydrocarbon and n-hexadecane hydrocarbon, the inventive method, under the condition that natural acid feed stock conversion is higher, can obtain higher n-tetradecane hydrocarbon and hexadecane hydrocarbon yield.

The method that natural acid of the present invention prepares n-tetradecane hydrocarbon or n-hexadecane hydrocarbon comprises following content: natural acid and solvent, carry out hydrogenation reaction in the presence of a catalyst and hydrogen, catalyzer is palladium/carbon nano-tube catalyst, the reaction pressure of hydrogenation reaction is 1 ~ 10MPa, be preferably 2 ~ 8MPa, temperature of reaction is 220 ~ 320 DEG C, is preferably 260 ~ 300 DEG C, reaction times is 3 ~ 10 hours, is preferably 4 ~ 7 hours.

In the inventive method, hydrogenation process can adopt intermittent reaction, also can adopt continuous reaction.

In the inventive method, when adopting intermittent reaction, preferably carry out under agitation, the volume ratio of natural acid and catalyzer is l.0 ~ 2.5:0.2 ~ 0.5.

In the inventive method, when adopting continuous reaction, hydrogen and liquid phase (natural acid and solvent) volume ratio are in normal conditions 100:1 ~ 1200:1, are preferably 300:1 ~ 800:1.

In the inventive method, the NH preferably containing 5 ~ 50 μ L/L in the hydrogen that hydrogenation reaction uses ₃, be preferably 10 ~ 20 μ L/L, to improve the selectivity of object product n-tetradecane hydrocarbon and n-hexadecane hydrocarbon.

In the inventive method, natural acid raw material can be the industrial raw material such as Palmiticacid (palmitinic acid) or n-teradecanoic acid (tetradecanoic acid).

In the inventive method, solvent is one or more in normal hexane, normal heptane, octane or dodecane, and the volume ratio of natural acid and solvent is: l.0 ~ 2.5:7 ~ 20.

In the inventive method, catalyzer take multi-walled carbon nano-tubes as carrier, with the palladium of mass percentage 2% ~ 10% for active ingredient.Multi-walled carbon nano-tubes is common commercial goods.

The preparation method of used catalyst of the present invention is as follows: under 50 ~ 100 DEG C of conditions, with the HNO of 2 ~ 8Mol/L ₃multi-walled carbon nano-tubes is carried out oxide treatment 1 ~ 5h, then filters, be washed to neutrality, 100 ~ 150 DEG C of oven dry; Then be added to the water, ultrasonic disperse, add H by the mass percentage 2% ~ 10% of palladium in catalyzer ₂pdC1 ₄solution, adds formaldehyde solution after stirring, and regulates PH value to 8 ~ 11 with Na0H solution, stirs, filters, washes, dries, obtain Pd/MWCNTs catalyzer.

Find through large quantity research, method of the present invention, to the hydrogenation deoxidation of natural acid, there is very high catalytic activity and object product (n-tetradecane hydrocarbon and n-hexadecane hydrocarbon) selectivity, the decarboxylic reaction that carbon number is reduced and decarbonylation reaction little, when particularly containing a small amount of ammonia in hydrogen, the selectivity of object product is higher.

Compared with prior art, the feature that the present invention has is: 1, catalyst preparation process is simple, can be recycled; 2, temperature of reaction significantly reduces, and is the production process of less energy-consumption; 3, solvent load is few, cheap and easy to get, and boiling point is low, is easy to recycle.; 4, this process operation is flexible;

5, object product selectivity is high, is conducive to subsequent separation process.

Embodiment

Embodiment 1

Catalyst preparing

6M HNO is used in 80 DEG C of oil baths ₃multi-walled carbon nano-tubes (length 5 ~ 15 μm, nanometer port, Shenzhen company limited provides for commercial goods, purity >95%, diameter 40 ~ 60nm) is carried out oxide treatment 2h, then filters, be washed to neutrality, 120 DEG C of oven dry; Get above-mentioned oxidation-treated carbon nanotube, add 70mL water, ultrasonic disperse.

Be that active ingredient adds H by the palladium of mass percentage 2% ~ 10% ₂pdC1 ₄solution, formaldehyde solution is added after stirring, by 1M NaOH solution adjust ph to 9, stir 25min, filter, massive laundering, dry, obtain Pd/ multi-walled carbon nano-tubes catalyzer (Pd/MwCNTs), prepare two kinds of catalyzer and catalyzer 1(palladium mass content is 4%) catalyzer 2(palladium mass content is 7%).

Embodiment 2

2.5 parts of (parts by volume, lower same) Palmiticacid, 0.3 part of Pd/MwCNTs catalyzer 1 and 20 parts of normal hexanes are added in 100mL reactor, is filled with the hydrogen (NH containing 5 μ L/L ₃), initial hydrogen pressure 5.0MPa, opens and stirs and heating, stopped reaction after 280 DEG C of reaction 6h, to be cooled to room temperature, filters to isolate catalyzer.

Carry out detection by quantitative by gas-chromatography to product, the transformation efficiency of known raw material Palmiticacid is 99%, and the total recovery of product n-hexadecane hydrocarbon is 95%(molar yield, and product n-hexadecane hydrocarbon accounts for the per-cent of raw material Palmiticacid).

Embodiment 3

1.5 parts of n-teradecanoic acids, 0.4 part of Pd/MwCNTs catalyzer 2 and 16 parts of normal hexanes are added in 100mL reactor, is filled with the hydrogen (NH containing 5 μ L/L ₃), initial hydrogen pressure 5.0MPa, opens and stirs and heating, stopped reaction after 260 DEG C of reaction 7h, to be cooled to room temperature, filters to isolate catalyzer.

Carry out detection by quantitative by gas-chromatography to product, the transformation efficiency of known raw material n-teradecanoic acid is 98%, and the yield of product n-tetradecane hydrocarbon is 95%(molar yield, and product n-tetradecane hydrocarbon accounts for the per-cent of raw material n-teradecanoic acid).

Embodiment 4

By 2.5 parts of (parts by volume, down together) Palmiticacid, 0.3 part of Pd/MwCNTs catalyzer 1 and 20 parts of octanes add in 100mL reactor, be filled with hydrogen, initial hydrogen pressure 5.0MPa, open and stir and heating, stopped reaction after 280 DEG C of reaction 6h, to be cooled to room temperature, filter to isolate catalyzer.

Carry out detection by quantitative by gas-chromatography to product, the transformation efficiency of known raw material Palmiticacid is 99%, and the total recovery of product n-hexadecane hydrocarbon is 91%(molar yield, and product n-hexadecane hydrocarbon accounts for the per-cent of raw material Palmiticacid).

Claims

1. the method for n-tetradecane hydrocarbon or n-hexadecane hydrocarbon prepared by a natural acid, it is characterized in that comprising following content: natural acid and solvent, carry out hydrogenation reaction in the presence of a catalyst and hydrogen, catalyzer is palladium/carbon nano-tube catalyst, the reaction pressure of hydrogenation reaction is 1 ~ 10MPa, and temperature of reaction is 220 ~ 320 DEG C, and the reaction times is 3 ~ 10 hours, natural acid is palmitinic acid or tetradecanoic acid, the NH containing 5 ~ 50 μ L/L in the hydrogen that hydrogenation reaction uses ₃.

2.. in accordance with the method for claim 1, it is characterized in that: the reaction pressure of hydrogenation reaction is 2 ~ 8MPa, and temperature of reaction is 260 ~ 300 DEG C, and the reaction times is 4 ~ 7 hours.

3. in accordance with the method for claim 1, it is characterized in that: hydrogenation process adopts intermittent reaction, reaction is carried out under agitation, and the volume ratio of natural acid and catalyzer is l.0 ~ 2.5:0.2 ~ 0.5.

4. in accordance with the method for claim 1, it is characterized in that: hydrogenation process adopts continuous reaction, and hydrogen and liquid phase volume ratio is in normal conditions 100:1 ~ 1200:1.

5. in accordance with the method for claim 1, it is characterized in that: the NH containing 10 ~ 20 μ L/L in the hydrogen that hydrogenation reaction uses ₃.

6. in accordance with the method for claim 1, it is characterized in that: solvent is one or more in normal hexane, normal heptane, octane or dodecane, the volume ratio of natural acid and solvent is: l.0 ~ 2.5:7 ~ 20.

7. in accordance with the method for claim 1, it is characterized in that: catalyzer take multi-walled carbon nano-tubes as carrier, in catalyst quality containing active component palladium 2% ~ 10%.

8. in accordance with the method for claim 7, it is characterized in that: the preparation method of catalyzer is as follows, under 50 ~ 100 DEG C of conditions, with the HNO of 2 ~ 8Mol/L ₃multi-walled carbon nano-tubes is carried out oxide treatment 1 ~ 5h, then filters, be washed to neutrality, 100 ~ 150 DEG C of oven dry; Then be added to the water, ultrasonic disperse, add H by the mass percentage 2% ~ 10% of palladium in catalyzer ₂pdC1 ₄solution, adds formaldehyde solution after stirring, and regulates PH value to 8 ~ 11 by NaOH solution, stirs, filters, washes, dries, obtain Pd/MWCNTs catalyzer.